# Quantum computing progress is better judged by useful results

Markdown copy of https://realalpha.app/s/quantum-computing-progress-is-better-judged-by-useful/ on Real Alpha, the best minutes from long interviews with the people building AI. Cite and link the page, not this copy.

- Speaker: [Roman Yampolskiy](https://realalpha.app/people/roman-yampolskiy/) · Roman Yampolskiy is a computer scientist, AI safety researcher, and professor at the University of Louisville. · Coined the term AI safety and directs the University of Louisville's Cyber Security Lab.
- Host: [Joe Rogan](https://realalpha.app/people/joe-rogan/) · Host, The Joe Rogan Experience
- Show: The Joe Rogan Experience
- Episode: [Joe Rogan Experience #2345 - Roman Yampolskiy](https://realalpha.app/v/j2i9D24KQ5k/), Jul 3, 2025
- Moment: 31:39 to 33:55 of the episode (2 min), playing on https://realalpha.app/s/quantum-computing-progress-is-better-judged-by-useful/; the episode from there: https://realalpha.app/v/j2i9D24KQ5k/?t=1899

## Quote

> “In reality, I think the largest number we can factor is like 15, literally, **not 15 to a power**, like just 15.”
> — [Roman Yampolskiy](https://realalpha.app/people/roman-yampolskiy/) at [32:37](https://realalpha.app/v/j2i9D24KQ5k/?t=1957) · The Joe Rogan Experience

## Takeaways

1. Qubit counts aren’t comparable measures across architectures.
2. He says the largest Shor’s-algorithm factoring result was only 15.
3. Quantum advantages so far concern narrow problems, not general computing.

## About this segment

Roman Yampolskiy says qubit counts obscure whether quantum computers can solve practical problems. He cites factoring 15 as the largest Shor’s-algorithm result he knew of, not evidence of broad computing power.

From “Joe Rogan Experience #2345 - Roman Yampolskiy”, Jul 3, 2025. [Watch the full episode](https://realalpha.app/v/j2i9D24KQ5k/)

## Transcript

Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.

[31:44](https://realalpha.app/v/j2i9D24KQ5k/?t=1904) And then algorithmic progress itself is also exponential. And then you have quantum computing. So that's the next step. It's not even obvious that we'll need that. But if we ever get stuck, yeah, we'll get there. I'm not too concerned yet. I don't think there are actually good quantum computers out there yet. But I think if we get stuck for 10 years, let's say, that's the next paradigm. So what do you mean by you don't think there's good quantum computing out there?

[32:12](https://realalpha.app/v/j2i9D24KQ5k/?t=1932) So we constantly see articles coming out saying we have a new quantum computer. It has that many qubits. Right. But that doesn't mean much because they use different architectures, different ways of measuring quality. To me, show me what you can do. So there is a threat from quantum computers in terms of brain and cryptography, factoring large integers. And if they were actually making progress, we would see with every article, now we can factor 256-bit number, 1024-bit number.

[32:43](https://realalpha.app/v/j2i9D24KQ5k/?t=1963) In reality, I think the largest number we can factor is like 15, literally, not 15 to a power, like just 15. There is no progress in applying it to Shor's algorithm last time I checked. But when I've read all these articles about quantum computing and its ability to solve equations that would take conventional computing an infinite number of years, and it can do it in minutes. Those equations are about quantum states of a system.

[33:13](https://realalpha.app/v/j2i9D24KQ5k/?t=1993) It's kind of like, what is it for you to taste ice cream? You computed so fast and so well, and I can't, but it's a useless thing to compute. It doesn't compute solutions to real-world problems we care about on conventional computers. I see what you're saying. So it's essentially set up to do it quickly. It's natural for it to accurately predict its own states, quantum states, and tells you what they are.

[33:37](https://realalpha.app/v/j2i9D24KQ5k/?t=2017) And a classic computer would fail miserably. Yes, it would take billions and billions of years to compute that specific answer. But those are very restricted problems. It's not a general computer yet. When you see these articles, when they're talking about quantum computing,